Garbage disposal unit



p 23, 1958 T. H. MAHONEY, JR 2,853,240

GARBAGE DISPOSAL UNIT Filed Oct. 15, 1956 2 Sheets-Sheet 1 M [avail Jar j amyfl Sept. 23, 1958 "r. H. MAHONEY, JR 2,853,240

GARBAGE DISPOSAL UNIT Filed Oct. 15, 1956 2 Sheets-Sheet 2 United States Patent 2,853,240 GARBAGE DISPOSAL UNIT Thomas H. Mahoney, Jr., Natick, Mass. Application October 15, 1956, Serial No. 6 1 5,8 6 Claims. (Cl. 241 -38) This invention relates to a garbage disposal unit. and has for its principal objects to provide a mobile unitfor receiving garbage as it is collected and reducing it en route to a comminuted semiliquid condition for disposal from time to time by discharging it from the unit. into the sewage system of the city or town within which the collection is being made, thereby to eliminate longhauls to a dump and hence to provide for economical disposal of garbage and use of the disposal equipment. Other possible places of disposal are piggeries or fertilizer plants where the liquid garbage may be discharged onto perforated moving belts and delivered thereby to the place of feeding or a place of chemical treatment for conversion into fertilizer. Another object is to provide a unit in which the semiliquid garbage may be kept agitated at all times so that it does not tend to. congeal within the unit. Other objects are to provide a unit which may easily be kept clean without garaging for that purpose, which has relatively few operating parts to require up,- keep, is durable and is efficient in operation.

'As herein illustrated the unit is mobile, being in. the form of a motor chassis or tractor drawn chassis supporting a large capacity body within which the garbage is deposited pending discharge. The bottom of the body has an inner concave floor and has an opening. at its lowest point which is normally covered by a closure. mem. her, the latter being movable to uncover the opening when desired to empty the body. The body is. provided with means for receiving a deposit of garbage and meansfor reducing the garbage after deposit therein to a semiliquid pulp by grindingand for discharging the ground garbage in a pile substantially vertically above the closed bottom opening. Preferably the aforesaid means, is. a receptacle mounted across the back end of the truck into which the garbage is deposited for transferto a grinder. From the grinder the garbage is discharged. into the body. The garbage may be transferred from the receptacleto the grinder" by a screw conveyor or the receptacle may be elevated and itself discharge the garbage into the grinder. In the latter case a power operated hoe may be provided to withdraw the garbage from the bucket. To keep the garbage in a fluid state paddles are mounted in the body above the bottom to stir it constantly. If desired screws may be placed at the bottom so as to assist in discharging the garbage. Additionally jets are mounted within the body near its top and at the bottom adjacent the bottom opening through which fluid maybe ejected. Those at the top are adapted to eject water at high pressure, for example, from a fire hydrant with suflicient force to deplete and wash' the piled mass through the discharge opening at the bottom. The jets at the bottom are for adding liquid to the mass to keep it liquid.

If desired hot water or steam may be ejected through'the nozzles to sanitize the apparatus.

The invention will now be described in .greater detail with reference to the accompanying drawings wherein: Fig. 1 is a side elevation of a truck supporting garbage disposal unit;

2,853,24d Patent d Sept. 23, 1958 Fig. 2 is a plan View of Fig. 1 with the top omitted and with certain parts in section;

Fig. 3 is a vertical section taken on the line 33 of Fig. 2;

Fig. 4 is a section showing a disposal tube connected to the discharge;

Fig. 5 is an elevation partly in section of an alternative form of disposal unit;

Fig. 6 is an elevation partly in section of still another form of disposal unit; and

Fig. 7 is a plan view of means for assisting in discharge of the garbage.

In one form of the invention a tank body 10 is mounted on a truck chassis 12, the former having a flat bottom 14, vertical side and end walls 16 and 13 and a top 20. The bottom has a circular discharge opening 22 (Fig. 2) which is located substantially centrally thereof. Within the body above the bottom 14 there is a secondary bottom or floor 24 (Fig. 3) which slopes from the sides and ends down to the opening 22 and which has an opening in it concentric with the opening 22 so that garbage deposited on the floor will gravitate toward and through the opening 22 when the latter is open, assisted by water from high pressure jets, as will subsequently be described.

At the rear end of the body (Figs. 1 to 3). there is mounted transversely of the chassis a trough 26 which is open at the top for receiving garbage. Within the trough there is mounted a screw 28 having right and lefthand helices for moving garbage deposited therein, in opposite directions toward its opposite ends; Nearthe ends of the trough there are rifled passages 30 within which the end portions of the screws turn and which cooperate therewith to grind the garbage forced through them into a semiliquid mass. Below the rifled passages 30 (Fig. 3) there are discharge openings '32 through which the masticated garbage is forced into chambers 34 located near the bottom of the trough within which are located the lower ends of upwardly inclined screws 36 which rise forwardly through the floor 24 and upwardly within the tank body to a place substantially vertically above the opening 22 at the top. The upwardly rising screws 36 are housed within tubular casings 40 and the latter have near their upper ends discharge openings 42 (Fig. 1) through which comminuted garbage carried upwardly through the tubes by the screws is discharged downwardly in a heap or pile directly above the bottom opening. As will be seen by reference to Fig. 2 the screws converge as they rise so as to discharge as nearly together as is practical.

Much garbage contains greases and oils which congeal during cold weather consequently there is a tendency for the garbage to solidify at the bottom of the body and hence not to be readily fiowable when it is desirable to discharge the filled truck. Accordingly, a plurality of paddles 44 (Fig. l) are mounted along a shaft 46, the latter being journaled longitudinally of the body in a horizontal position in suitable end bearings for rotation so as constantly to agitate the garbage close to the bottom.

The drive for the screw 28, the screws 36 and the shaft 46 may conveniently be taken from a common source on the vehicle, for example the truck motor, from a separate motor mounted on the truck chassis or if desired individual motors may be provided for each screw. As herein illustrated the letter M is intended to denote a motor drive for the screws or shafts or transmission means for connecting the screws or shafts to a source of power.

The bottom opening 22 (Fig. 4) is normally covered by a sliding gateor closure 48 which is manually operable by a suitable lever 50 to be withdrawn to permit discharge of garbage or tobe returned to cover the opening after the tank body is emptied; Preferably a plate 37 is welded to the bottom which has a boss 38 concentric with the opening 22 for receiving the closure 48 and has at its lower extremity an external coarse thread to which a flexible conduit 52 may be coupled by a collar 53 for conducting the garbage therefrom into the sewer opening thus to avoid dissemination of unpleasant odor and to prevent spilling any of the garbage on the street.

For the purpose of better discharge of the garbage nozzles 54 are mounted on the bottom 24 (Fig. 6) adjacent the bottom opening through which water may be ejected into the comminuted mass. Other nozzles 55 (Figs. 1 and 2) are mounted near the top of the body, for example at the corners, through which water or steam may be ejected for the purpose of scavenging. The nozzles 54 are supplied with water while en route, for example from a water tank T mounted on the top of the tank body. The nozzles 55 may be supplied with high pressure water by way of a lateral C which may be connected to a fire hydrant. The high pressure water from the hydrant supplies sufficient force to deplete and wash the piled mass through the discharge opening. For the purpose of sanitizing the apparatus the lateral may be connected to a fire hydrant, a suitable source of live steam or hot water at a place of garaging. Water ejected from the nozzles 54 dilutes the garbage, making it more flowable, while the high pressure water ejected from the nozzles 55 serve to disintegrate the congealed mass and this helps to clear the interior of the tank body.

As shown in Figs. 1 to 3 inclusive, the trough 26 for receiving the garbage is located near the bottom substantially at waist level so that a bucket of garbage may be easily lifted to the top opening and its content dumped thereinto. The grinding, that is, reduction of the garbage to a soft mastic mass takes place as previously explained in the trough.

An alternative form of apparatus is shown in Fig. 5, wherein the tank body 10 is substantially similar to that described heretofore in so far as the bottom, sides and end are concerned, the top differing however by an added upwardly projecting blister or chamber 152 for receiving the upper end of the screw 36. The lower end of the screw is located in a horizontally arranged tray 154 and serves to conduct garbage disposed therein upwardly into the chamber 152. In this form there is no screw or other means within the trough 154 for grinding the garbage or otherwise reducing it to a mastic form prior to delivery to the upper part of the tank body. Below the upper end of the screw at the top of the tank body there is a grinder in the form of a pair of horizontally arranged, parallel shafts 56 carrying intermeshing cutting blades 58 for grinding garbage discharged from the upper end of the screw and depositing it in a heap above the bottom opening 22. The grinding elements are closed within walls 60 so that the garbage is required to pass between them.

Because of the possibility that someone may catch his hand or arm in a screw mechanism, such as shown in Figs. 1 to inclusive, by reaching down into the trough, a third form of the invention is shown in Fig. 6. In lieu of a fixed trough at the back of the body a skip bucket 62 is mounted at the rear end for vertical movement from a position substantially at waist height to the top of the tank body for raising garbage placed in it upwardly to the top for discharge through a top opening 64 (Fig. 6) provided at the top. Vertical movement of the skip bucket may be accomplished in any suitable manner and as herein shown the bucket has a pivoted forward wall 66 which swings downwardly and forwardly when the bucket is raised, for example to clear the top of the body so that the garbage in the bucket may be discharged forwardly therefrom into the opening 64. To efiect discharge a power operated hoe 68 is mounted on the top of the tank body at the end of a rod 70 extending from a hydraulic cylinder 72. Normally the hoe is held in an extended position, 'as shown in Fig. 6, so that as the bucket rises it enters the bucket close to the rear wall, penetrating through the garbage to the bottom. When the bucket comes to rest with its forward wall tipped downwardly the cylinder 72 is supplied with hydraulic pressure through a line 73 connected, for example, to a pump Pm fastened to the underside of the chassis, to retract the hoe and cause it to drag the garbage forwardly from the bucket into the opening 64. After the garbage is withdrawn from the bucket the hoe is restored to its initial position and the skip lowered. Initial movement of the skip bucket automatically restores the wall 66 to its vertical position. Below the opening 64 within the body there is grinding means 74 constituted by a pair of parallel shafts 76 on which there are mounted cutting blades 78 which intermesh and grind garbage disposed thereon. The grinding members 74 are enclosed within a housing 80 which has at its lower side a discharge opening 82 for conducting the ground garbage to the lower end of a screw 84 located within a cylindrical housing 86. The screw 84 and housing 86 rise forwardly and upwardly through the body to the top within a blister or chamber 88. The upper end of the housing 86 has an opening 90 through which the garbage carried upwardly by the screw is discharged substantially vertically above the bottom opening 22.

The two alternate forms of the apparatus as described in Figs. 5 and 6, are as in the form illustrated in Figs. 1 to 4 inclusive, provided with agitating means, bottom closures, and with jets for supplying water and/ or steam.

Under some circumstances it is conceivable that even with the agitating means described and with the high pressure water there will still be a tendency for the garbage as it accumulates to become so packed down as to be diflicult to move or at least to start. Hence as shown in Fig. 7, there may be one or more shallow gutters 94 pressed into the bottom which radiate outwardly from the discharge opening, in which operate screws 95. Rotation of the screws beneath the mass will move the garbage downwardly along the gutters to the discharge opening.

It is to be understood that in each form of the invention the important aspect is to conduct the garbage to a point for mastication, deposit it in a mastic or semiliquid condition above the discharge opening in a condition to be discharged into the sewer system of a city or town so that the apparatus may be employed continuously without having to travel to a place of dumping. Such equipment it is obvious would be particularly suitable for densely populated areas where large quantities of garbage will be picked up within a relatively small area and where large fleets of garbage disposal trucks would ordinarily have to be employed if at each filling the truck had to travel long distances to dispose of its load before it could be returned to use.

Itshould be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A mobile garbage disposal unit comprising a pick-up truck mounting a tank which has a bottom with downwardly sloping walls, at the lowest part of which there is a discharge opening, means including a hopper located externally of the tank for receiving garbage and depositing it in comminuted form in the tank near the top substantially vertically above the bottom opening, a closure normally closing the bottom opening so that garbage deposited within the tank piles up on the bottom above the bottom opening, an agitator arranged within the tank near the bottom on a line crossing the bottom opening, a plurality of nozzles arranged adjacent the bottom for supplying water to the garbage, means for effecting continuous operation of the first-named means and the agitator, means for supplying water to the nozzles to dilute the mass, and means for opening the closure to discharge the diluted mass.

2. A mobile garbage disposal unit comprising a pick-up truck mounting a tank which has a bottom with downwardly sloping walls, and at the lowest part of which there is a discharge opening, a hopper at the rear end of the tank body for receiving garbage, grinding elements at the bottom of the hopper for comminuting garbage deposited therein, a conveyor for conducting the garbage comminuted by the grinder from the hopper to a point near the top of the tank body substantially vertically above the bottom opening, a closure normally covering the bottom opening so that garbage conducted to the top of the tank falls to the bottom and piles up above the bottom opening, an agitator arranged within the tank near the bottom on a line crossing the bottom opening, a plurality of nozzles arranged adjacent the bottom for supplying water to the garbage, means for effecting continuous operation of the grinding elements, conveyor and the agitator, means for supplying water to the nozzles, and means for opening the closure to discharge the diluted mass.

3. A mobile garbage disposal unit comprising a pick-up truck mounting a tank which has a bottom with downwardly sloping walls, at the lowest part ofwhich there is a discharge opening, a hopper extending across the rear end of the tank body substantially at waist level, grinding means at the bottom of the hopper having oppositely threaded screws for grinding and extruding the ground garbage toward the opposite ends of the hopper, a conveyor screw at each end of the hopper rising therefrom internally to the top of the tank body for conducting garbage from the hopper to the top of the tank body and discharging it substantially vertically above the bottom opening so that it piles up on the bottom above the bottom opening, an agitator arranged in the tank near the bottom on a line crossing the bottom opening, a plurality of nozzles arranged adjacent the bottom for supplying Water to the garbage piled up on the bottom, means for effecting continuous operation of the grinding means, conveyor and agitator, means for supplying water to the nozzles to dilute the mass, and means for opening the closure to discharge the diluted mass.

4. A disposal unit according to claim 3, wherein said screws converge to a point at the top of the body substantially vertically above the bottom opening.

5. A mobile garbage disposal unit comprising a pick-up truck mounting a tank which has a bottom with downwardly sloping walls, at the lowermost part of which there is a discharge opening, and a top with a charging opening, a skip bucket at the rear end of the tank body for receiving garbage, means for elevating the skip bucket to a level with the top opening, and discharging the garbage into the opening, means below the opening for grinding the garbage and discharging it in a pile substantially vertically above the bottom opening, a closure normally covering the bottom opening, an agitator arranged within the tank near the bottom adjacent the bottom opening, a plurality of nozzles arranged near the bottom, means for eifecting elevation of the skip bucket, means for effecting continuous operation of the grinding means and the agitator, means for supplying water to the nozzles to dilute the mass, and means for opening the closure to discharge the diluted mass.

6. A disposal unit comprising a wheeled chassis, a tank body supported on the chassis having an internally concave bottom, walls and a top, said bottom having an opening atits lowest point of concavity, a closure normally covering the opening, means for moving the closure to uncover the opening, said tank body having a top opening at its rear end, a skip bucket at the rear end of the body for receiving garbage, means for elevating the bucket to the level of the top opening, a power operated hoe arranged to enter the bucket as it rises to its top position, said bucket having a hinged forward wall released by movement of the bucket to its top position to take up a substantially horizontal position in the plane of its bottom, said power operated hoe being operable to draw the garbage in the bucket across the bottom and open wall into the top opening, a grinder below the opening into which the garbage falls and is comminuted, and a screw conveyor for transferring the ground garbage from the grinder to a point near the top, substantially vertically above the bottom opening.

7. A mobile garbage disposal unit comprising a pick-up truck mounting a tank which has a bottom with downwardly sloping walls, at the lowermost part of which there is a discharge opening, a hopper crossing the rear end of the tank body at substantially Waist level for receiving garbage, a screw conveyor mounted on the tank body with one end in the hopper and its other end at the top of the tank body substantially vertically above the bottom opening for elevating garbage deposited in the hopper to the top of the body, a grinder located subjacent the discharge end of the screw for comminuting garbage delivered to it by the screw, a closure normal-1y covering the bottom opening so that garbage discharged from the grinder piles up in a heap on the bottom above the bottom opening, an agitator located near the bottom of the tank adjacent the bottom opening, a plurality of nozzles adjacent the bottom, means for effecting continuous operation of the screw conveyor, grinder and agitator, means for supplying Water to the nozzles to dilute the mass, and means for opening the closure to discharge the diluted mass.

8. In a disposal unit according to claim 1, a conduit couplable to the bottom subjacent the bottom opening for conducting garbage from the bottom of the disposal unit into the open manhole of a sewer system.

9. In a disposal unit according to claim 1, one or more screws located parallel to the bottom and radially toward the discharge opening for forcibly discharging garbage through said opening.

10. In a disposal unit according to claim 1, one or more shallow gutters in the bottom radiating from the discharge opening and a screw located in each gutter for for- 'cibly moving garbage .at the bottom of the pile toward the discharge opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,152,303 Davidson Aug. 31, 1915 1,405,952 Stuart Feb. 7, 1922 1,780,064 Buzzo Oct. 28, 1930 1,863,964 Brenner June 21, 1932 2,110,207 Doren Mar. 8, 1938 2,431,161 Bjorklund Nov. 18, 1947 2,594,054 McNamara et al Apr. 22, 1952 

